LAUSR

Temperature is an important environmental factor in agriculture, affecting individual organisms and the entire farmland ecosystem. Global warming has become more tangible, which may negatively affect pest biological control due to the generally weak thermal tolerance of natural enemies. The mirids Cyrtorhinus lividipennis and Tytthus chinensis (Insecta: Hemiptera: Miridae) are important natural predators of planthoppers and leafhoppers in Asian paddy fields. However, the effects of thermal stress on these predators remain poorly understood. We investigated the thermal tolerance, fitness, predation abilities, and transcriptomic response of T. chinensis and C. lividipennis at elevated temperatures. T. chinensis was more heat tolerant than both Nilaparvata lugens (its prey) and C. lividipennis. T. chinensis not only exhibited better development, survival, reproduction, and predation capacities compared with C. lividipennis but also showed stronger competitiveness when the two mirid predators co-persisted under high-temperature conditions. To understand the underlying mechanisms, we sequenced their transcriptomes at different temperatures. Heat shock protein (HSP) genes were identified and analyzed due to their high co-regulation during heat treatment. Quantitative polymerase chain reaction results showed that T. chinensis induces HSPs expression quickly and strongly over a wider temperature range in response to heat stress compared with C. lividipennis. Taken together, we highlighted the potential of T. chinensis as a biological control agent in future global warming conditions and provided insight into the thermal adaption of mirid species.